The present disclosure relates to an optical recording medium such as an optical disc, for example.
Various reproduction-only discs and recordable discs (a write-once disc, a rewritable disc) are developed under the category of a CD (Compact Disc), a DVD (Digital Versatile Disc), a Blu-ray Disc (registered trademark), and the like.
In the field of such optical discs, for example, a further increase in the capacity based on high density recording is being sought with respect to next-generation discs.